<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
     <!-- 最新版本的 Bootstrap 核心 CSS 文件 -->
     <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css"
     integrity="sha384-HSMxcRTRxnN+Bdg0JdbxYKrThecOKuH5zCYotlSAcp1+c8xmyTe9GYg1l9a69psu" crossorigin="anonymous">
 <script src="../js/jquery-3.6.0.js"></script>
 <!-- 最新的 Bootstrap 核心 JavaScript 文件 -->
 <script src="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/js/bootstrap.min.js"
     integrity="sha384-aJ21OjlMXNL5UyIl/XNwTMqvzeRMZH2w8c5cRVpzpU8Y5bApTppSuUkhZXN0VxHd"
     crossorigin="anonymous"></script>
     <STYLE></STYLE>
</head>
<body>
    <div class="btn-group btn-group-justified" role="group" aria-label="...">
        <div class="btn-group" role="group">
          <button type="button" class="btn btn-default">Left</button>
        </div>
        <div class="btn-group" role="group">
          <button type="button" class="btn btn-default">Middle</button>
        </div>
        <div class="btn-group" role="group">
          <button type="button" class="btn btn-default">Right</button>
        </div>
      </div>
</body>
</html>